efi: fix obviously-wrong type hints

* the VM.set_efi_var prototype was shown wrong by.

  lib/vm.py:400: error: "str" has no attribute "as_str"  [attr-defined]
  lib/vm.py:401: error: "str" has no attribute "as_str"  [attr-defined]

* get_secure_boot_guid was never meant to return None (had to follow the
  code to convince myself, hope I did not miss anything), so avoid calling
  .get():

  lib/efi.py:120: error: Incompatible return value type (got "GUID | None", expected "GUID")  [return-value]

* _get_efi_signature_list only ever returns bytes, not str as advertised
  (remants of py3 conversion?)

  lib/efi.py:385: error: Incompatible return value type (got "bytes", expected "str")  [return-value]


Signed-off-by: Yann Dirson <[email protected]>

Author: ydirson

lib/efi.py

@@ -122,7 +122,7 @@ def get_secure_boot_guid(variable: str) -> GUID:
         'KEK': global_variable_guid,
         'db': image_security_database_guid,
         'dbx': image_security_database_guid,
-    }.get(variable)
+    }[variable]
 
 
 def cert_to_efi_sig_list(cert):
@@ -149,7 +149,7 @@ def cert_to_efi_sig_list(cert):
     )
 
 
-def certs_to_sig_db(certs):
+def certs_to_sig_db(certs) -> bytes:
     """Returns a signature database from a list cert file paths."""
     if isinstance(certs, str):
         certs = [certs]
@@ -380,7 +380,7 @@ def copy(cls, other, name=None):
 
         return obj
 
-    def _get_efi_signature_list(self) -> str:
+    def _get_efi_signature_list(self) -> bytes:
         if self.is_null:
             return b''
 

lib/vm.py

@@ -387,7 +387,7 @@ def sign_efi_bins(self, db: efi.EFIAuth):
                 signed = db.sign_image(local_bin)
                 self.scp(signed, remote_bin)
 
-    def set_efi_var(self, var: str, guid: str, attrs: bytes, data: bytes):
+    def set_efi_var(self, var: str, guid: efi.GUID, attrs: bytes, data: bytes):
         """Sets the data and attrs for an EFI variable and GUID."""
         assert len(attrs) == 4